Abstract
A real-time holographic interferometry technique is suggested for recording the isopachic patterns corresponding to transparent anisotropic composites. The isochromatic and isopachic patterns are obtained for a transparent glass-epoxy composite disk with a central hole subjected to diametral compression. A method is suggested for interpreting the optical data and to obtain the separate values of stress components. Its application is demonstrated.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Abbreviations
- E ρ ,E t :
-
orthotropic-elastic moduli
- F ρ ,F t ,F ρ t :
-
orthotropic-stress-optic constants
- G ρt :
-
orthotropic shear modulus
- K 1,K 2 :
-
nondimensional constants
- K σ :
-
transmission isopachic-fringe constant
- \(\bar K_\sigma\) :
-
reflection isopachic-fringe constant
- S ij :
-
compliance elements
- t :
-
thickness of specimen
- gfrp:
-
glass-fiber-reinforced plastic
- ∈ρ, ∈ t :
-
orthotropic strain components
- ∈ p :
-
thickness-direction strain component
- ν pℓ :
-
∈ p /∈ℓ
- ν pt :
-
∈ p /∈ t
- στ, σ t , τℓt :
-
orthotropic stress components
- θ:
-
observed isoclinic angle
- θσ :
-
principal stress angle
References
Pih, H. andKnight, C.E., “Photoelastic Analysis of Fiber Reinforced Composites,”J. Comp. Matls.,3, (1),94–107 (Jan.1969).
Netrebko, V.P., Zlenko, L.S. andKaphaninova, S.S., “Photoelastic Investigation of the State of Stress and Strain of Anisotropic Bodies,”Vestnik Moskowskogo Universiteta, Ser 1,24 (6),78–83, (Nov./Dec.1969).English Translation, Moscow Univer. Mech. Bull. 24 (6), 47–51 (1972).
Sampson, R.C., “A Stress Optic Law for Photoelastic Analysis of Orthotropic Composites,”Experimental Mechanics,10 (5),210–215 (May1970).
Dally, J.W. andPrabhakaran, R., “Photoelastic Analysis of Orthotropic Composites”Experimental Mechanics,11, (9),346–356 (Aug.1971).
Pipes, R.B., andRose, J.L., “Strain Optic Law for Certain Class of Birefringent Composites,”Experimental Mechanics,14 (9),355–374 (Sep.1974).
Chandrashekhara, K. and Jacob, K.A., “Experimental Numerical Hybrid Technique for Stress Analysis of Orthotropic Composites,” Chapt. 5, Developments in Composite Materials, ed. by G.S. Holister, Applied Science Publishers (1977).
Jacob, K.A., “Stress Analysis of Composites through Photoanisotropic Elasticity,”J. Indian Instit. of Sci.,62 (A),129–150 (July1980).
Knight, C.E., Jr. andPih, H., “Shear Difference Method and Application in Orthotropic Photoelasticity,”J. Engrg. Mats. and Tech., ASME,98 (4),369–374 (Oct.1976).
Chandrashekhara, K. andJacob, K.A., “A Numerical Method for Separation of Stresses in Photo-orthotropïc Elasticity,”Experimental Mechanics,18 (2),61–66 (Feb.1978).
Rowlands, R.E., Dudderar, T.D., Prabhakaran, R. andDaniel, I.M., “Holographically Determined Isopachics and Isochromatics in the Neighborhood of a Crack in a Glass Composite,”Experimental Mechanics,20, (2),53–56 (Feb.1980).
Post, D., “Holography and Interferometry in Photoelasticity,”Experimental Mechanics,12 (3),113–123 (March1972).
Dudderar, T.D. andO'Regan, R., “Measurement of the Strain Field Near a Crack Tip in Polymethylmethacrylate by Holographic Interferometry,”Experimental Mechanics,11 (2),49–56 (Feb.1971).
Jacob, K.A. and Dayal, V., “On Two-dimensional Stress Analysis by Isopachics,” IVth Inter. Congress on Exper. Mech., Boston (May 1980).
Chandrashekhara, K., Jacob, K.A. andPrabhakaran, R., “Towards Stress Freezing in Birefringent Orthotropic Composite Models,”Experimental Mechanics,17 (8),317–320 (Aug.1977).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Jacob, K.A., Dayal, V. & Ranganayakamma, B. On stress analysis of anisotropic composites through transmission optical patterns: Isochromatics and isopachics. Experimental Mechanics 23, 49–54 (1983). https://doi.org/10.1007/BF02328681
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02328681